<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package	Zend_Search_Lucene
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license	http://framework.zend.com/license/new-bsd	 New BSD License
 */


/**
 * @category   Zend
 * @package	Zend_Search_Lucene
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2008 Zend Technologies USA Inc. (http://www.zend.com)
 * @license	http://framework.zend.com/license/new-bsd	 New BSD License
 */
abstract class Zend_Search_Lucene_Storage_Directory
{

	/**
	 * Closes the store.
	 *
	 * @return void
	 */
	abstract public function close();

	/**
	 * Returns an array of strings, one for each file in the directory.
	 *
	 * @return array
	 */
	abstract public function fileList();

	/**
	 * Creates a new, empty file in the directory with the given $filename.
	 *
	 * @param string $filename
	 * @return Zend_Search_Lucene_Storage_File
	 */
	abstract public function createFile($filename);


	/**
	 * Removes an existing $filename in the directory.
	 *
	 * @param string $filename
	 * @return void
	 */
	abstract public function deleteFile($filename);

	/**
	 * Purge file if it's cached by directory object
	 * 
	 * Method is used to prevent 'too many open files' error
	 *
	 * @param string $filename
	 * @return void
	 */
	abstract public function purgeFile($filename);
	
	/**
	 * Returns true if a file with the given $filename exists.
	 *
	 * @param string $filename
	 * @return boolean
	 */
	abstract public function fileExists($filename);


	/**
	 * Returns the length of a $filename in the directory.
	 *
	 * @param string $filename
	 * @return integer
	 */
	abstract public function fileLength($filename);


	/**
	 * Returns the UNIX timestamp $filename was last modified.
	 *
	 * @param string $filename
	 * @return integer
	 */
	abstract public function fileModified($filename);


	/**
	 * Renames an existing file in the directory.
	 *
	 * @param string $from
	 * @param string $to
	 * @return void
	 */
	abstract public function renameFile($from, $to);


	/**
	 * Sets the modified time of $filename to now.
	 *
	 * @param string $filename
	 * @return void
	 */
	abstract public function touchFile($filename);


	/**
	 * Returns a Zend_Search_Lucene_Storage_File object for a given $filename in the directory.
	 *
	 * If $shareHandler option is true, then file handler can be shared between File Object
	 * requests. It speed-ups performance, but makes problems with file position.
	 * Shared handler are good for short atomic requests.
	 * Non-shared handlers are useful for stream file reading (especial for compound files).
	 *
	 * @param string $filename
	 * @param boolean $shareHandler
	 * @return Zend_Search_Lucene_Storage_File
	 */
	abstract public function getFileObject($filename, $shareHandler = true);

}

